Acoustic stylus mounting



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Nov. 6 11923.

F. TUCHFARBER ACOUSTIC STYLUS MOUNTING Filed Dec. 5. 1920 vwmtoz %mk Wu 2351 44 &bbc mwa; I

Patented Nota ti, rasa,

FRANK TUCHFARBER, OF CINCINNATI, OHIO.

ACOUSTIC STYLUS HOUNTING.

Application filed December 3, 1920. Serial No. &27,932.

To ai? whom it may conccrn:

Be it known that FRANK TUCHFARBER, a citizen of the United States, and a resi dent of Uincinnati, in the county of Hamilton and State ot Ohio, have invented certnin new and useful Improvements in Acoustic Stylus Mountings, oi: which the 'following is a spccification.

My invention relates to sound-reproduc` ing machines such as phonographs, gramophones, and the like, and its object is to improve the quality of the sound reproduced by such instruments.

My invention consists in the combination of parts and in the details of Construction and arrangement of parts, as Will hereinafter be more 'fully described and claimed.

In the drawings:

Fig. l is a side elevation of a sound box of a sound-reproducing machine and its Stylus provided with my invention;

Fig. 2 is a detail perspective view ot a device embodying my invention;

Fig. 3 is an enlarged sectionon a plane corresponding to the line 3-3 of Fig. 1;

Fig. i is a cross-section on the same scale as Fig. 3 on a plane corresponding to the line 4- 4 ot Fig. l;

Fig. 5 is a partial cross-section corresponding to Fig. 3, but showing how the invention adapts itself to a thinner Stylus; and

For the purpose of illustrating the use of my invention, I have shown, in the drawing, a sound-box l With a diaphragin 2, to which is attached one end of the Stylus lever 3 suitably mounted :for correct movement by means of the mounting t on thelower'side of the sound-box l. and having in its lower end a holder 5 which has` opening' downwardly 'from its lower end, a socket 6 of triangular cross-section (Fig. 4) as these sockets usually made to adapt them'tor receiving either a Stylus of triangular cross*- section usually made of Wood or fiber, or a stylus oi' circular cross-section usually made ot' steel or other metal. Some sound-reproducing mz'chines, however. have this socket circular in cross-section, these usually einploying a metal Stylus having a tip of other metal or a gem of some kind. The mecha` nism, as here shown, is disposed for use With records havinglateral undulations, but, as will be discerned from the following description, my invention is applicable also in connection with records having vertical undulations or those of other forms, and may be applied to reproducing mechanisms of varying constructions and types, the one herein shown being selected merely to illustrate the principles of the invention' As is well known, the needles or styli are ordinarily mounted directly in the socket 6 whatever be the shape of the socket, and are held by the set-screw 7 clamping directly against the side of the needle or Stylus. lt the needle or stylus be of metal, either with the point of the same material or of some other material, as just mentioned, the density of the metal in the stylus is suiicient, not only to faithfnlly transmit the -desired sound vibrations, but also 'to transmit certain undesirable vibrations due to imperfection in the correlation of certain parts of the mechanism, and especially to irregu` larity in the cooperation of the Stylus With certain parts of the record undulations, so that they, with the most desirable kinds of diaphragms, which, in the majority of apparatus, are of mica, produce blasting or harsh and strident sounds at certain periods in the rendition of some selections.

To overcome these defects of the metal needle or stylus, as well as with the idea of decreasin'g the wear on certain kinds ot reeords, needles or styli ot various softer materials have been employed, notably various kinds of Vegetable materials, such as certain Woods, as Well as some other materials which are less dense than metals. Some of these somewhat overcome the transmission of the undesirable sounds or noises, but they are objectionable in that they also fail to transmit many of the desired vibrations, so that they are generally incapable ot' reproducing a selection with the proper tone, and usually fail to reproduce sufliciently loud to be satisfactory. Moreover, while such softer materials save some wear on the records, they are themselves qui kly worn out and are not dependable for very many repeated uses.

As between these two kinds of needles or styli, the metal needle or Stylus, either with its point of the same or a harder material, is preferred by most users of sound-reproducing apparatus because other considerations being equal, the metal needle or Stylus permits of a more faithful reproduction, and, it the ordinary steel needle or Stylus, is readily renewed at each rendition, or it tipped with a suiciently hard material and used With records intended thcrefor, will EOB continue; to i giye taithful reproduction throughout a great number of successive renditions Without notieeable deterioration, either of the needle or stylus, or the records.

It is the purpose oI" my invention to overcome the defects of the metal needle or Stylus of either one of the kinds just alluded to, without naterially reduoing its eteetiveness for faithful tone reproduction and loudness.

Inmy invention, lha ve introduced a ina terahhaving considerable resiliency and density, and therefore capable of approximatng metalin its- Capacity 'for transmtting all of the desired vbrations tromthe record tothe diaphragm yet having` such an amount otelasticity not possessed by metals that harsh, strident, blastingeffects in certain parts ot certain renditions are avoided.

Such a material -isexemplified by a'hard fiber such as that used extensyely in electricalinsulation work Such hard fibery which is i n ade froni materials of Vegetable origin butcompressed to suehan-extent that the natural Vegetable properties so objectionable in ordinarynaturalfiber needles or styli are eliininated, is toughand strong similar-to Other 'inaterialslhaving the just described v characteristics may be substitutedfor -the hard fiber` justalluded to,-and it Will be understood that-my' invention not limited to the use of this particular material Inen; tioned as' an example. 'It Will' be understood, -however, that to be satisfactory for the purpose of ny invention, the material should h ave considerable strength and toughness and suficient density to transmit desired sound Vibrations, and have suflicient elastcty when-used according to' my invention to prevent the apprecable passage of undesirable Vibratiomwhich latter Vibrations are usually of greator amplitude than the desired ones. i i In using ths hard fiber or equivalent material I- do not attempt to substitute it ffor the material ot the `stylus'or needle, either in thetp or the body thereof Onthe contrary my invention comprchends the use in t any given sound-reproducing apparatus of the kind of needle or stylus particularly a dapted to the apparatus and to therecords it is 'designed to cooperate withyas, for. in-. stance in many kinds of apparatus, the ordi nary steel needle, to berenewediat eachirendition, gives them ost satistactorymesults,

y While in other apparatus needles With tips of hard material tonpermanent useare'enployed Myinventon is applicabie .to either kind of apparatus and -is adaptedto eliini natesuch detects as the severalkinds of ap: paratus have, Without any apprecable diminution of thedesired tone reproducing fa:

cilities.

Such materials as eXernpltied by the hard fiber' do not have' suficent stifiness to constitute a satistaotory :needle or Stylus I body nor sufieient hardness to be at all Satisi'actory in the point of the stylus. At the sametime, they are so dense that they are not adapted to be employed n large masscs as holders for the metal stylextending out' r from the stylus lever ot' the apparatus, as has' been the case With certain other materials'used forthe same general purpose as ny nvention. a i

My invent ion difl'ers froni the various other devices tor this same g eneral purpose in the respects due to the decided difference of the kind oi material employed, which is too soft and too *Weak to be employed as the Stylus or needleitselt', and too stifl' and dense to be enployed as a protruding part ot' the stylus:suppertine;structure; and yet which is so strong and tough, as Well as -dense and':hard, that it inay form a 'fairly .permanent partot the apparatus ,when properly reinforced by beingheld in the socket G itself 111 the Storm of a short tube or holloW cylinder S, open at each end and longitudi nally with its outer walls fitting against the Wal'ls ot' the socket 6 and itsinner Walls more' or less tightly .fitting the outer surface ot the needle'or stylus9. If so used and clan'ped by theset-screw 7'With theright dee gree ot tightness it virtually becomes one with the needle or' stylusand the stylus lever :tor the taithtul transmission of correct'tone 'vib *ations and `at the same time acts due to its considerable elasticity,toabsorb undesirable Vibrations Without transmtting them i certained by actual .trial With the given record. i v i i v :As shown heroin, the needle or stylus isthe ordinary kind usually made of steel or some other suitable' metal; While. as before Inen-- tionechthe socket is triangular as many ot them are for the purpose of'reeeiving. tri- ,angularstyli of various soft materials.. It Wlll ibe understood, however;` that my invsn tion `is useful With the various tipped styli whchhave round tipped shanks and are in some apparatus fitted into around sockets.

Also, some apparatus einploying the or di-' nary metal ueedles have round sockets to re ceive the needles. In any case it will be;understood that the tube or hollow 'cylinder 8, according, to my inventiom should be of the approximate outer diameterto readily enter but not too loosely fit the socket whether it be triangular, round orother shape, and of the right internal 'diameter to receive the shank 'of the thickest needle or stylus desired tobe employed. In any instance, the soc'ket is usually of considerably greater diameter or transverse dimension than is the thickest needle or stylus which it is to hold; so that itis permissibl'e to have the tube or hollow cylinder or bushing 8 of ample thickness to give it the desired Operating effect, as well as to make it strong enough to properly resist the disru-ptive tendencies of repeated clampings by the 'set-screw 7. `With hard fiber, such as I pre-'fer to use and with the thickness permis'si'ble in the usual socket and with the hea'viest steel needle, the -bushing 8 will remain serviceable for the rendition of thousands of selections if ordinary care be observed in clamping it.

In the preferred form of my invention I coat the inner wall of the cylinder 8 with a varnish or other suitable coating material which is elastic yet semi-hard and afiords a surface not easily marred by the insertion of the needle. This varnish in my preferred form of my invention is applied to one surface of the fibrous material while in sheet form and after it has dried I cut the varnished brous material into lengths, run it through a tube forming machine and then cut the tubes or cylinders into the required lengths. These cylinders by reason of the longitudinal slit 10 can be reduced in diameter to facilitate insertion into the socket 6 and when in the socket tend to enlarge and automatically hold therein. They can also be expanded to readilyi receive needles of varying sizes. The material of the bushing preferably overlaps along the slit 10.

It will be understood that this bushing 8 remains in the socket 6 throughout the period of its use, being retainedtherein either by the friction of its outer sides with the socket walls (Fig. 6) or if it be slightly loose therein, by leaving the set-screw 7 clamped tightly enough to retain it when the needle or stylus 9 is to be removed. Used in this way, it is not only very inexpensive, but causes practically no inconvenience, because the needle or stylus is inserted into it as reaclily as into the soclet 6, were the socket not provided with the bushing 8, With apparatus having a permanent stylus, the bushing; 8 remains as permanently as the stylus itself. and the only wear or tear to which it is exposed is the slight change of adjustment which the user may desire, to reduce the volume of tone transmitted.

Also, due to its resiliency, such material as is exemplified by the hard fiber is capable of considerable yielding to adjust itself to needles or styli of somewhat less diameter than the internal diameter of the bushs is seen in F g. 5, As here shown, the

wall of the tube or cylinder 8 flexes inwardly under the pressure of the clamping screw 7 where diminution of the Volume has heretofore been resorted to by extending the needle 'or stylus out considerably from the holder, the use of my invention permits the needle or stylus to be set as far in as possible. In either case, it is thus possible to not merely obtain ample Volume in the sound, but to render many sounds faithfully, which, with the thinner needles or styli or with the eXtended adjustments, were almost wholly lost. Heavy metal needles or styli or short extensions of them from the holder have been discouraged in apparatus as heretofore provided, because with these provisions, the blasting in certain parts of most renditions is extremely disagreeable; with the result that users sacrifice many of the fine and pleasing details of selections, as they had to in using the thinner or more eXtended styli, in order to avoid the positively disagreeable noises which must attend the use of a heavy stylus or one adjusted to render all of the details of the selection.

It will therefore be understood that while the device is adjustable to various thicknesses of styli, it generally renders the use of thinner needles or styli, unnecessary, because it practically eliminates all of the objectionable consequences which dictated the use of such thinner styli.

So` far as the thinner needles or styli were useful where reduced Volume was desired, as in small rooms, this reduction of Volume is practically attained with my invention by very slightly loosening the clamping upon the bushing or tube 8 as hereinbefore described. This reduces the Volume satisfactorily in such cases and at the same time, does not lose the fine and pleasing details of the rendition as is often the case where a thinner needle or stylus is substituted, or where the needle or stylus is extended far from the holder in order to reduce the Volume of sound transmitted.

The heavy needle or stylus, not extended so far from the holder as to lose important parts of the rendition due to its own flexi bility, is the best means for transmitting to the diaphragm 2 all of the correct tone vibrations, whether this needle or stylus be the ordinary metal kind or one tipped with a hard material. My improved bushing or mounting 8 of hard fiber or equivalent materal is adapted to Permit such a needie or Stylus, soadjusted, to function prctically to its maximum extent inthe respects just noted, and at the same time to prevent such needle or Stylus transmittng undesirable noises. v e g L What I claim is:

1. A stylus mounting independent .of 'the .Stylus and the holder` therefof, .composed of a, Stylus bushn'g adapted to substantially surround styli of various sizes, said bushin'g formed of a fbrous nateriaiand provided With a longtudnal opening ;extendng throughoutthe length of the Wall thereof so as to permit increase or decrease in the size of the bushing ,g i 1,473,ee3

lndi'ical elastie bushing independent of 'but dapted to substantially* surround acoustic styli ofivarious siz es, said bushing having a long'tndnalepening in the Wall th ereof, .se as to ermit the cylindrical sizeof said bushingvto bechanged to accommodate styl of various sizes.

Alcylindricl styli nio nt-ing provided `W1th an'penng in the Wall thereof where'by the cylindrical sizeof said mounting may i be changed to accommodate styliof various slzes, sa d bushng formed .of a, resihent material oat'ed onthe nner face wthan elastc 'Varnish adapted to maintain the mountng at its normal ;cylindrcal sizeg whi1epernitting same to be readily changed g to aceommodate styli of various szes.: 2. 'A stylusmo nting cons sting of a cy`-.

FRANK TUCHFARBER; i 

